Obliquity – Maths and morality
Let’s get the boring bit out of the way first: mathematics.
The primary meaning of ‘oblique’ which the Oxford Online English Dictionary cites is ‘neither parallel nor at right angles to a specified or implied line’ or, in a word, ‘slanting’. So obliquity is the state of being slanted or divergent. Naturally this is a pretty useful term in maths (geometry specifically) and it has specialised meanings when describing lines, surface, angles and 3D shapes.
It gets a little more interesting when applied to anatomy (but we’re still talking about science). As a noun it refers to the abdominal muscle which runs down our side; as an adjective it can also describe a muscle which is ‘neither parallel nor perpendicular to the long axis of a body or limb’.
What exactly that means, and why biology felt the need to hijack a perfectly lovely word in order to describe it, I’m not entirely sure. Of course all these specific uses of ‘oblique’ are jargon, and I realise that I’m not pleading its case very strongly in detailing the ways in which the sciences use it.
But of course there’s a little more to it; my literary genes wouldn’t allow me to focus an entire blog post on a maths word.
Just as the idea of obliquity has been seized by scientists on one side and come to describe a technical, tangible state, philosophers and other such creative minds have treated the key idea of divergence from an implied line (as in the primary definition) slightly differently.
The noun, which entered Middle English at the turn of the 14th century as ‘obliquitee’ (from the Middle French ‘obliquite’, derived itself from Latin) can now also describe divergence from moral conduct, or an instance of it. Collins Dictionary gives, after simply ‘a deviation from the perpendicular or horizontal, ‘a moral or mental deviation’. It can also be synonymous with ‘indirect’ as in ‘he issued an oblique attack on the President‘.
Just as science can give words a more precise meaning, the rest of us can make them more abstract. And it’s incredibly pleasing that we can have both the exact and the immaterial contained in such an elegant little noun.